Mikhail Svetlov/Getty Images(MOSCOW) — The Kremlin denied Friday that Russian President Vladimir Putin’s claims that Russia has tested a new generation of nuclear weapons were intended to start a renewed arms race with the United States.

“The president said this should absolutely not be seen as the beginning of an arms race,” Putin’s spokesman, Dmitry Peskov, told reporters in a briefing call on Friday, saying it was an “asymmetric response” to U.S. efforts to develop an anti-missile shield.

The day before, Putin had used an annual state of the nation speech to tout an arsenal of new doomsday weapons, including nuclear-armed underwater drones and a nuclear-powered cruise missile.

Putin, who added that the missiles were invulnerable to interception, said the weapons were entirely defensive and that they were intended to preserve the nuclear balance between the U.S. and Russia.

Uncertainty quickly emerged surrounding the existence of the weapons. Meanwhile, U.S. officials downplayed some of Putin’s claims, saying that the nuclear-powered cruise missile was not yet operational and had crashed during recent testing.

Putin, however, presented the weapons as fundamentally new and as lifting Russia into a new stage of military power that would keep it on par with the U.S. for the foreseeable future.

“This is not a bluff,” Putin told an audience of Russia’s elite gathered for the speech near the Kremlin. “The attempt to contain Russia has failed.”

Standing in front of giant screens, Putin played a series of videos that mostly demonstrated the half-dozen weapons in clunky computer graphic simulations. One of the videos showed a simulation of warheads from a new heavy intercontinental ballistic missile called the “Sarmat.”

Regarding another weapon, a hypersonic nuclear missile called “Avangard,” Putin described it as falling to earth “like a burning sphere.” Speaking about the nuclear-power cruise missile, Putin told the audience that “no one else in the world had anything like it.”

“It would be wrong to interpret it as some militarist statement,” Peskov told reporters.

Peskov said Putin’s unveiling of the weapons was “nothing but the response” to the U.S.’s withdrawal from the Cold War-era Anti-Ballistic Missile Treaty in 2002, which prohibited the deployment of ballistic missile defense systems.

“Russia is not going to get dragged into any arms race,” Peskov said.

Russia is not developing systems to “neutralize” its opponents’ strategic nuclear forces, he said, insisting that its new weapons were about restoring parity, not challenging it.

The Pentagon’s chief spokeswoman, Dana White, on Thursday denied the missile shield was the reason for the Russian weapons.

“They know very well that it’s not about them,” she told reporters.

The Pentagon largely shrugged at Putin’s menacing comments. White said it was “not surprised” by Putin’s announcement and that the U.S. was fully prepared.

Putin’s speech came as the U.S. unveiled its own new nuclear arms policy — and after President Trump has spoken of massively rebuilding the country’s nuclear arsenal. The Trump administration’s new Nuclear Posture Review specifically identified Russian efforts to develop new types of weapons as a risk to be countered.

A State Department spokesman said Putin’s speech confirmed that Russia was violating its arms treaty obligations — in particular, the Intermediate-Range Nuclear Forces Treaty (INF). The U.S. and Russia have both previously accused each other of violating the INF.

Peskov said Russia “categorically denies” any violation.

Putin put on the weapons show less than three weeks before a presidential election, and it appeared geared most toward stirring feelings at home around Russian martial strength before the vote. The first three-quarters of Putin’s speech took up a pre-election pitch, making a series of optimistic promises for Russia’s development before he abruptly launched into the weapons demonstration.

Most of the weapons, such as the Sarmat missile, have been known to be in development for years. But experts have expressed surprise around the nuclear-powered cruise missile, which Putin said was a modified X-101 missile.

The U.S. tried to develop its own nuclear-powered cruise missile in the 1960s, but abandoned it.